6.4.8 Quality codes of the OPC HDA server
Quality codes
The quality code is required to check the status and quality of the raw data. The following table
shows the quality codes of OPC HDA.
Code OPC Description Quality
0x00040000 OPCHDA_RAW Provides information on the quality of
the value transfer of raw data.
GOOD
BAD
UNCERTAIN
0x00080000 OPCHDA_CALCULATED Provides information on the quality of
the value transfer of calculated data.
GOOD
BAD
UNCERTAIN
0x00100000 OPCHDA_NOBOUND No bounding values were found at the
start or end time.
BAD
0x00200000 OPCHDA_NODATA No raw data was found for the
specified period.
BAD
0x00400000 OPCHDA_DATALOST Raw data was not completely archived
during the selected period.
BAD
Additional information is available in the "OPC Historical Data Access Specification 1.20" of
the OPC Foundation.
6.4.9 Write access supported by the OPC HDA server
Introduction
The OPC HDA specification of the OPC Foundation also defines write access to archived data.
Note
PCS 7 is a process control system. In a process control system, archived data must not be
modified. For this reason, write access to archived data using OPC HDA has not been
enabled.
OpenPCS 7 interface
6.4 OPC Historical Data Access (OPC HDA)
OpenPCS 7
54 Function Manual, 05/2012, A5E02780178-02
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